An operational amplifier circuit is a circuit unit that can amplify a signal. Operational amplifier circuits are generally connected to one or more feedback networks to perform certain functions. The operational amplifier circuit can be implemented as either a discrete device or a semiconductor chip.
For normal operation of an operational amplifier circuit, a fixed supply voltage has to be supplied by a peripheral circuit. When failure of the peripheral circuit occurs, which causes the supply voltage to exceed a normal-operation voltage, the operational amplifier circuit cannot operate normally and internal devices may be damaged.